Search Option: Case Sensitive (Case)

If you click the Case button on the search toolbar to turn on the "case sensitive" search option, then the difference between lowercase and uppercase letters is taken into account. E.g. "Dog" will considered to be different from "dog". Otherwise, "dog", "Dog", "DOG", and even "doG" are all the same.

See also

Search|Prepare to Search
Search Options
Search Option: Adapt Case